You can ovveride default wall method search / listing posts paramter for method `OssnWall->getPublicPosts()`

Working example is OssnBlock component that trims posts from newsfeed if user is blocked.

~~~
<?php
function my_component_init(){
ossn_add_hook('wall', 'getPublicPosts', 'my_component_hook');
}
function my_component_hook($hook, $type, $params, $extra_params){
//you may alter $params , it contain order_by, etc.
//$extra_params contain $extra_params['user'] which is OssnUser instance
// it also contain $extra_params['friend_guids'] which are friends guids of user.
error_log(print_r($params, true));
error_log(print_r($extra_params, true));
return $params;
}
ossn_register_callback('ossn', 'init', 'my_component_init');
~~~